user/sven/linux.git/arch/powerpc/include, branch v4.9.220

powerpc/archrandom: fix arch_get_random_seed_int()

2020-01-29T09:24:00Z

commit b6afd1234cf93aa0d71b4be4788c47534905f0be upstream. Commit 01c9348c7620ec65 powerpc: Use hardware RNG for arch_get_random_seed_* not arch_get_random_* updated arch_get_random_[int|long]() to be NOPs, and moved the hardware RNG backing to arch_get_random_seed_[int|long]() instead. However, it failed to take into account that arch_get_random_int() was implemented in terms of arch_get_random_long(), and so we ended up with a version of the former that is essentially a NOP as well. Fix this by calling arch_get_random_seed_long() from arch_get_random_seed_int() instead. Fixes: 01c9348c7620ec65 ("powerpc: Use hardware RNG for arch_get_random_seed_* not arch_get_random_*") Signed-off-by: Ard Biesheuvel Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191204115015.18015-1-ardb@kernel.org Signed-off-by: Greg Kroah-Hartman

powerpc: Fix vDSO clock_getres()

2019-12-21T09:42:17Z

[ Upstream commit 552263456215ada7ee8700ce022d12b0cffe4802 ] clock_getres in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res(). In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; and hrtimer_resolution depends on the enablement of the high resolution timers that can happen either at compile or at run time. Fix the powerpc vdso implementation of clock_getres keeping a copy of hrtimer_resolution in vdso data and using that directly. Fixes: a7f290dad32e ("[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel") Cc: stable@vger.kernel.org Signed-off-by: Vincenzo Frascino Reviewed-by: Christophe Leroy Acked-by: Shuah Khan [chleroy: changed CLOCK_REALTIME_RES to CLOCK_HRTIMER_RES] Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/a55eca3a5e85233838c2349783bcb5164dae1d09.1575273217.git.christophe.leroy@c-s.fr Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/math-emu: Update macros from GCC

2019-12-21T09:41:22Z

[ Upstream commit b682c8692442711684befe413cf93cf01c5324ea ] The add_ssaaaa, sub_ddmmss, umul_ppmm and udiv_qrnnd macros originate from GCC's longlong.h which in turn was copied from GMP's longlong.h a few decades ago. This was found when compiling with clang: arch/powerpc/math-emu/fnmsub.c:46:2: error: invalid use of a cast in a inline asm context requiring an l-value: remove the cast or build with -fheinous-gnu-extensions FP_ADD_D(R, T, B); ^~~~~~~~~~~~~~~~~ ... ./arch/powerpc/include/asm/sfp-machine.h:283:27: note: expanded from macro 'sub_ddmmss' : "=r" ((USItype)(sh)), \ ~~~~~~~~~~^~~ Segher points out: this was fixed in GCC over 16 years ago ( https://gcc.gnu.org/r56600 ), and in GMP (where it comes from) presumably before that. Update the add_ssaaaa, sub_ddmmss, umul_ppmm and udiv_qrnnd macros to the latest GCC version in order to git rid of the invalid casts. These were taken as-is from GCC's longlong in order to make future syncs obvious. Other parts of sfp-machine.h were left as-is as the file contains more features than present in longlong.h. Link: https://github.com/ClangBuiltLinux/linux/issues/260 Signed-off-by: Joel Stanley Reviewed-by: Nick Desaulniers Reviewed-by: Segher Boessenkool Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

powerpc/83xx: handle machine check caused by watchdog timer

2019-12-05T14:34:51Z

[ Upstream commit 0deae39cec6dab3a66794f3e9e83ca4dc30080f1 ] When the watchdog timer is set in interrupt mode, it causes a machine check when it times out. The purpose of this mode is to ease debugging, not to crash the kernel and reboot the machine. This patch implements a special handling for that, in order to not crash the kernel if the watchdog times out while in interrupt or within the idle task. Signed-off-by: Christophe Leroy [scottwood: added missing #include] Signed-off-by: Scott Wood Signed-off-by: Sasha Levin

KVM: PPC: Book3S HV: Flush link stack on guest exit to host kernel

2019-11-28T17:29:06Z

commit af2e8c68b9c5403f77096969c516f742f5bb29e0 upstream. On some systems that are vulnerable to Spectre v2, it is up to software to flush the link stack (return address stack), in order to protect against Spectre-RSB. When exiting from a guest we do some house keeping and then potentially exit to C code which is several stack frames deep in the host kernel. We will then execute a series of returns without preceeding calls, opening up the possiblity that the guest could have poisoned the link stack, and direct speculative execution of the host to a gadget of some sort. To prevent this we add a flush of the link stack on exit from a guest. Signed-off-by: Michael Ellerman [dja: straightforward backport to v4.14] Signed-off-by: Daniel Axtens Signed-off-by: Greg Kroah-Hartman

powerpc/book3s64: Fix link stack flush on context switch

2019-11-28T17:29:06Z

commit 39e72bf96f5847ba87cc5bd7a3ce0fed813dc9ad upstream. In commit ee13cb249fab ("powerpc/64s: Add support for software count cache flush"), I added support for software to flush the count cache (indirect branch cache) on context switch if firmware told us that was the required mitigation for Spectre v2. As part of that code we also added a software flush of the link stack (return address stack), which protects against Spectre-RSB between user processes. That is all correct for CPUs that activate that mitigation, which is currently Power9 Nimbus DD2.3. What I got wrong is that on older CPUs, where firmware has disabled the count cache, we also need to flush the link stack on context switch. To fix it we create a new feature bit which is not set by firmware, which tells us we need to flush the link stack. We set that when firmware tells us that either of the existing Spectre v2 mitigations are enabled. Then we adjust the patching code so that if we see that feature bit we enable the link stack flush. If we're also told to flush the count cache in software then we fall through and do that also. On the older CPUs we don't need to do do the software count cache flush, firmware has disabled it, so in that case we patch in an early return after the link stack flush. The naming of some of the functions is awkward after this patch, because they're called "count cache" but they also do link stack. But we'll fix that up in a later commit to ease backporting. This is the fix for CVE-2019-18660. Reported-by: Anthony Steinhauser Fixes: ee13cb249fab ("powerpc/64s: Add support for software count cache flush") Cc: stable@vger.kernel.org # v4.4+ Signed-off-by: Michael Ellerman [dja: straightforward backport to v4.14] Signed-off-by: Daniel Axtens Signed-off-by: Greg Kroah-Hartman

powerpc/futex: Fix warning: 'oldval' may be used uninitialized in this function

2019-10-07T16:53:11Z

[ Upstream commit 38a0d0cdb46d3f91534e5b9839ec2d67be14c59d ] We see warnings such as: kernel/futex.c: In function 'do_futex': kernel/futex.c:1676:17: warning: 'oldval' may be used uninitialized in this function [-Wmaybe-uninitialized] return oldval == cmparg; ^ kernel/futex.c:1651:6: note: 'oldval' was declared here int oldval, ret; ^ This is because arch_futex_atomic_op_inuser() only sets *oval if ret is 0 and GCC doesn't see that it will only use it when ret is 0. Anyway, the non-zero ret path is an error path that won't suffer from setting *oval, and as *oval is a local var in futex_atomic_op_inuser() it will have no impact. Signed-off-by: Christophe Leroy [mpe: reword change log slightly] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/86b72f0c134367b214910b27b9a6dd3321af93bb.1565774657.git.christophe.leroy@c-s.fr Signed-off-by: Sasha Levin

powerpc/bpf: use unsigned division instruction for 64-bit operations

2019-07-10T07:55:33Z

commit 758f2046ea040773ae8ea7f72dd3bbd8fa984501 upstream. BPF_ALU64 div/mod operations are currently using signed division, unlike BPF_ALU32 operations. Fix the same. DIV64 and MOD64 overflow tests pass with this fix. Fixes: 156d0e290e969c ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Naveen N. Rao Signed-off-by: Daniel Borkmann Signed-off-by: Greg Kroah-Hartman

KVM: PPC: Book3S: Use new mutex to synchronize access to rtas token list

2019-06-22T06:17:23Z

[ Upstream commit 1659e27d2bc1ef47b6d031abe01b467f18cb72d9 ] Currently the Book 3S KVM code uses kvm->lock to synchronize access to the kvm->arch.rtas_tokens list. Because this list is scanned inside kvmppc_rtas_hcall(), which is called with the vcpu mutex held, taking kvm->lock cause a lock inversion problem, which could lead to a deadlock. To fix this, we add a new mutex, kvm->arch.rtas_token_lock, which nests inside the vcpu mutexes, and use that instead of kvm->lock when accessing the rtas token list. This removes the lockdep_assert_held() in kvmppc_rtas_tokens_free(). At this point we don't hold the new mutex, but that is OK because kvmppc_rtas_tokens_free() is only called when the whole VM is being destroyed, and at that point nothing can be looking up a token in the list. Signed-off-by: Paul Mackerras Signed-off-by: Sasha Levin

powerpc/booke64: set RI in default MSR

2019-05-16T17:43:47Z

commit 5266e58d6cd90ac85c187d673093ad9cb649e16d upstream. Set RI in the default kernel's MSR so that the architected way of detecting unrecoverable machine check interrupts has a chance to work. This is inline with the MSR setup of the rest of booke powerpc architectures configured here. Signed-off-by: Laurentiu Tudor Cc: stable@vger.kernel.org Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman